Hard butter including cacao butter is used extensively for foods in the filed of confectionary production and bread making, which primarily includes chocolate, and pharmaceuticals, cosmetics and the like. Such hard butter comprises, as a primary component, triglycerides (FMSOFMS) having one unsaturated bond in the molecule such as 1,3-dipalmitoyl-2-oleoylglycerin (POP), triglyceride having oleoyl group at the 2-position and each one of palmitoyl group and stearoyl group (POS), and 1,3-distearoyl-2-oleoylglycerin (SOS). There are also known triglycerides having two unsaturated bond in the molecule such as 1,3-distearoyl-2-linoleoylgrycerin (SLS) excellent as a hardness conditioning agent of chocolate.
In general, the above-described triglycerides are available as natural fats and oils containing such triglycerides, for example, palm oil, shea butter, sal fat, illipe butter and the like or fractioned oils thereof. Among these, palm oil is used as a fat and oil rich in POP, illipe butter is used as a fat and oil rich in POS, and shea butter, sal fat and the like are used as a fat and oil rich in SOS. For hard butter such as cacao butter equivalent, these fats and oils are usually used directly or by blending in an appropriate manner. However, since shea butter, sal fat, illipe butter and the like are obtained from wild plants, the yield and the price thereof significantly vary depending on factors such as weather. In the worst case, there is a problem that required quantity of such fat and oil is not ensured.
Thus, processes for preparing the above-described triglycerides, which use transesterification of particular fatty acids under 1,3-selective lipase, have been proposed (Patent Literatures 1 to 5), instead of obtaining the above-described triglycerides as fractionated oils of fats and oils such as palm oil, shea butter, sal fat and illipe butter. These Patent Literatures describe that lipases derived from Rhizopus sp., Aspergillus sp. and Mucor sp., pancreatic lipase and rice bran lipase are used as 1,3-selective lipase.
In the case of such transesterification, fatty acid after transesterification is usually recovered and hydrogenated to reuse. In this case, when plural kinds of fatty acids are used as the raw materials in order to prepare triglyceride such as POS wherein fatty acid residues at the 1,3-positions are different from each other, it is necessary to have additional steps for rebalancing composition of fatty acid raw material by analyzing the recovered fatty acid material and adding a lacking fatty acid(s) to the material.
Therefore, it is desired to develop more efficiently and more industrially suitable processes for preparing a hard butter as a cacao butter equivalent.
Patent Literature 1: JP-A-55-071797
Patent Literature 2: JP-B 03-069516
Patent Literature 3: JP-B 06-009465
Patent Literature 4: WO96/10643
Patent Literature 5: WO03/000832